1. Acid-Base Balance
KNH 413

2. Acid-Base Balance Acids Donate or give up H+ ions
Nonvolatile acids or fixed acids
Inorganic acids that occur through metabolism of CHO, protein, lipid
Average amount mmol/day
Proteins contribute the most
Lungs cannot eliminate

3. Acid-Base Balance Bases Can accept or receive H+ ions
Bicarbonate HCO3- elominating necessary to balance
Kidneys provide primary regulation
Kidneys are the main regulator of this acid base balance
Respiritory systems plays a big role, kidneys probably play biggest role

5. Acid-Base Balance pH Acidosis Accumulation of acid or loss of base
Contanstly fighting this in a TPN patient
If you have sodium choride make sure you balance it with sodium acetate
Acidemia
pH < 7.35
Main concern
Alkalosis
Accumulation of base or loss of acid
Alkalemia
Rarely occurs
pH > 7.45

6. Regulation of Acid-Base Balance
Chemical buffers
Bicarbonate is the number 1 buffer
Respiratory regulation
Increase the rate and depth of your breath
Body ability to use respiritory to extrete Co2
Increased Co2, for carbonic acid
Body is naturally trying to regulate it
Kidney regulation
Will work to release more bicarbonate if you are in an acidic state

8. Regulation of Acid-Base Balance
Respiratory regulatory control
Change in respiration rate
Depth of breathing
Release or retention of CO2– done by the body normally
In a medical setting you can set a vent
if they are in respiritory acidosis

9. Regulation of Acid-Base Balance
Renal regulatory control
If kidneys are functioning properly this is one of the first place that you want to look
Control of HCO3 by the kidneys
Increased or decreased based on need
Formation of dibasic phosphate and sulfur in the urine
Accepts H+
How much is going out to the urine and how much is being resurfaced
Bicarbonate will cause pH of body to rise-alkalosis

10. Contantly fighting acidosis in a ICU setting
We can work with metabollic acidosis by picking a TPN or enteral product that will help with the situtation

11. Regulation of Acid-Base Balance
Electrolyte Balance
Hydrogen and bicarbonate both electrolytes
Other electrolytes affected to maintain electroneutrality
Potassium, chloride, sodium

14. Acid-Base Disorders 4 major types Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis

16. Acid-Base Disorders Respiratory acidosis
Excess acid in blood secondary to carbon dioxide retention
Hypercapnia
Common causes
d/t respiratory dysfunction – renal regulatory systems compensate

18. Acid-Base Disorders Respiratory acidosis Labs Hypoxemia
Decreased pH, elevated pCO3
Slightly elevated bicarbonate
Increase in serum Ca, K, Cl
Hypoxemia
Restlessness, apprehension, lethargy, muscle twitching, tremors, convulsions, coma

19. Acid-Base Disorders Respiratory acidosis Treatment
Correct underlying condition
Increase oxygenation
Mechanical ventilation

20. Acid-Base Disorders Respiratory alkalosis
Relative excess amount of base d/t reduction of CO2
Hyperventilation
Common causes - see Table 9.6
Shift of acid from ICF to ECF
Bicarbonate moved into cells in exchange for chloride – renal compensation

22. Acid-Base Disorders Respiratory alkalosis pH > 7.45
Plasma HCO3 low in chronic, PaCO3 low in acute
Cardiac, CNS, respiratory symptoms
Treat underlying cause
Correction of hypoxia

23. Acid-Base Disorders Metabolic Acidosis
All types not caused by excessive CO2
Common causes
Diarrhea most common cause
d/t excessive loss of bicarbonate – bicarbonate- carbonic acid buffer system is stimulated

24. © 2007 Thomson - Wadsworth

28. Acid-Base Disorders Metabolic Acidosis Kussmaul breathing
Cardiac and neurological
Treat underlying cause
Raise pH to safe level – not too quickly

29. Acid-Base Disorders Metabolic Alkalosis Excess amount of base
Fluid imbalance – with volume decrease
Without fluid imbalance – without volume decrease
Common causes
Underlying event determines pathophysiology

32. Assessment of Acid-Base Disorders
© 2007 Thomson - Wadsworth